Re: limiting hint bit I/O

Robert Haas wrote:
> On Sat, Feb 5, 2011 at 10:37 AM, C?dric Villemain
> <cedric.villemain.debian@gmail.com> wrote:
> > Please update the commitfest with the accurate patch, there is only
> > the old immature v1 of the patch in it.
> > I was about reviewing it...
> >
> > https://commitfest.postgresql.org/action/patch_view?id=500
> 
> Woops, sorry about that.  Here's an updated version, which I will also
> add to the CommitFest application.
> 
> The need for this patch has been somewhat ameliorated by the fsync
> queue compaction patch.  I tested with:

Uh, in this C comment:

+        * or not we want to take the time to write it.  We allow up to 5% of
+        * otherwise-not-dirty pages to be written due to hint bit changes,

5% of what?  5% of all buffers?  5% of all hint-bit-dirty ones?  Can you
clarify this in the patch?

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + It's impossible for everything to be true. +